We show a pointwise estimate for the Fourier
transform on the line involving the number of times the function
changes monotonicity. The contrapositive of the theorem may be used to
find a lower bound to the number of local maxima of a function. We
also show two applications of the theorem. The first is the two weight
problem for the Fourier transform, and the second is estimating the
number of roots of the derivative of a function.

In this paper we derive formulas for summation of series involving
J.~Bourget's generalization of Bessel functions of integer order, as
well as the analogous generalizations by H.~M.~Srivastava. These series are
expressed in terms of the Riemann $\z$ function and Dirichlet
functions $\eta$, $\la$, $\b$, and can be brought into closed form in
certain cases, which means that the infinite series are represented
by finite sums.

Exact analytical expressions for the inverse Laplace transforms of
the functions $\frac{I_n(s)}{s I_n^\prime(s)}$ are obtained in the
form of trigonometric series. The convergence of the series is
analyzed theoretically, and it is proven that those diverge on an
infinite denumerable set of points. Therefore it is shown that the
inverse transforms have an infinite number of singular points. This
result, to the best of the author's knowledge, is new, as the
inverse transforms of $\frac{I_n(s)}{s I_n^\prime(s)}$ have
previously been considered to be piecewise smooth and continuous.
It is also found that the inverse transforms have an infinite
number of points of finite discontinuity with different left- and
right-side limits. The points of singularity and points of finite
discontinuity alternate, and the sign of the infinity at the
singular points also alternates depending on the order $n$. The
behavior of the inverse transforms in the proximity of the singular
points and the points of finite discontinuity is addressed as well.

In this paper, we provide a generalization of the classical Rao
bound for orthogonal arrays, which can be applied to ordered
orthogonal arrays and $(t,m,s)$-nets. Application of our new bound
leads to improvements in many parameter situations to the strongest
bounds (\ie, necessary conditions) for existence of these objects.